Bolt

Abstract

A bolt, wherein a small diameter guide (116) is formed at the terminal tip part of a shaft part (15) and threads (31) oppositely threaded to threads (30) formed in a fixed diameter part (115) are formed in the guide part. When the bolt (1) is inserted into a nut (100) in a tilted state and the threads (31) are engaged with the female screw part (105) of the nut (100), an effect to raise the bolt (1) occurs in the nut and, therefore, unless the bolt is positioned in a correct tightening attitude, it cannot be threaded into the nut (10). Accordingly, the bolt (1) can be securely prevented from being caught or seized into the nut (100). When the threads (31) are formed in an oppositely threaded double threaded screw, the effect can be further increased.

Description

technical field [0001] The present invention relates to bolts, and more particularly to bolts formed to prevent the bolt itself from being seized or jammed into a female threaded member. Background technique [0002] Conventionally, there have been so-called anti-seizure bolts that, when the bolt is obliquely inserted into the female thread member of the nut, guide its own posture appropriately with a guide portion formed on its bolt shank without any jamming. Make the bolt screw smoothly into the female threaded member. Although ordinary bolts have a shank with a substantially constant diameter, such anti-seize bolts are equipped with a small-diameter or tapered pilot at the front end of the shank so that when the pilot is aligned with the female thread member When the outer peripheral surfaces of the threaded holes are in contact, the posture of the bolt can be appropriately guided. For example, Patent Document 1 discloses a bolt in which...

AI Technical Summary

Problems solved by technology

Therefore, there is a problem that the bolt may deviate from the thread pitch when screwed into the female threaded member, which may also cause seizure and jamming.

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